PMC Residency Entrance Exam cheat sheet

Acute MI: ST elevation in two contiguous leads (or new LBBB) defines STEMI; troponin rise/fall with symptoms, ECG change, or imaging defines NSTEMI versus unstable angina (normal troponin).

Heart failure: HFrEF = LVEF ≤40%; first-line quadruple therapy is ACE inhibitor/ARB or ARNI, beta-blocker, MRA, and SGLT2 inhibitor.

Diabetic ketoacidosis: glucose >250 mg/dL, pH <7.3, bicarbonate <18 mEq/L, anion gap >10-12, ketonemia/ketonuria; treat with isotonic saline, insulin infusion, and potassium replacement once K <5.2 mEq/L.

Hyperkalemia ECG progression: peaked T waves → PR prolongation → widened QRS → sine wave; give IV calcium first if ECG changes are present.

Nephrotic syndrome: proteinuria >3.5 g/day, hypoalbuminemia, edema, hyperlipidemia; minimal change disease is the commonest cause in children.

Cirrhosis ascites: first-line is spironolactone plus furosemide; diagnostic paracentesis with SAAG ≥1.1 g/dL indicates portal hypertension.

Thyroid: primary hypothyroidism shows high TSH with low free T4; subclinical hypothyroidism shows high TSH with normal free T4.

Anemia classification by MCV: microcytic (<80) = iron deficiency, thalassemia, chronic disease; macrocytic (>100) = B12/folate deficiency, alcohol, hypothyroidism.

Rheumatoid arthritis: symmetric small-joint polyarthritis with morning stiffness >1 hour; anti-CCP is more specific than rheumatoid factor.

Acute appendicitis: migration of pain to right iliac fossa, McBurney point tenderness, and Alvarado score ≥7 supports operative management; ultrasound is preferred in children and pregnancy.

Small bowel obstruction: colicky pain, vomiting, distension, absolute constipation; erect abdominal film shows multiple air-fluid levels; initial management is nil by mouth, IV fluids, and nasogastric decompression.

Shock index (heart rate/systolic BP) >0.9 suggests significant occult hemorrhage in trauma; class III hemorrhage = 30-40% blood loss with hypotension and tachycardia.

Burns: Parkland formula = 4 mL × body weight (kg) × %TBSA of lactated Ringer's in 24 hours, half in the first 8 hours from injury.

Breast cancer: sentinel lymph node biopsy is standard for clinically node-negative axilla; triple assessment = clinical examination, imaging, and tissue sampling.

Thyroidectomy: recurrent laryngeal nerve injury causes hoarseness; external branch of superior laryngeal nerve injury causes loss of high pitch; hypocalcemia from parathyroid injury presents with perioral tingling.

Acute pancreatitis: diagnosis needs 2 of 3 - characteristic pain, lipase/amylase >3× upper limit, or imaging; Ranson and modified Glasgow scores predict severity.

Testicular torsion: high-riding testis with absent cremasteric reflex and transverse lie; surgical exploration is indicated within 6 hours to preserve viability.

Hernia: indirect inguinal hernia is lateral to inferior epigastric vessels and commonest in young males; direct hernia is medial and commonest in older men.

Estimated date of delivery: Naegele's rule = first day of last menstrual period + 7 days − 3 months (+1 year); ultrasound crown-rump length is most accurate in the first trimester.

Preeclampsia: new hypertension ≥140/90 mmHg after 20 weeks plus proteinuria ≥300 mg/24 h or organ dysfunction; delivery is the definitive treatment.

Postpartum hemorrhage: leading cause is uterine atony; first-line management is uterine massage plus oxytocin, then ergometrine, carboprost, or misoprostol.

Ectopic pregnancy: triad of amenorrhea, abdominal pain, and vaginal bleeding; transvaginal ultrasound shows empty uterus with beta-hCG above the discriminatory zone (~1500-3500 mIU/mL).

Fetal heart rate monitoring: early decelerations mirror contractions (head compression, benign); late decelerations follow contractions (uteroplacental insufficiency); variable decelerations indicate cord compression.

Contraception: combined oral pills are contraindicated in migraine with aura, smokers over 35, and history of venous thromboembolism.

Cervical cancer screening: Pap smear from age 21 or 25; HPV testing is more sensitive; colposcopy for abnormal results; HPV 16 and 18 cause most cases.

Ovarian torsion: sudden unilateral pelvic pain with nausea and an enlarged ovary on ultrasound; laparoscopy is both diagnostic and therapeutic.

Normal labor stages: first stage to full dilatation, second stage from full dilatation to delivery, third stage from delivery of baby to delivery of placenta (normally ≤30 minutes).

Neonatal resuscitation: initial steps are warmth, drying, stimulation, and airway positioning; positive pressure ventilation is the most important step for bradycardia <100/min.

APGAR score assesses Appearance, Pulse, Grimace, Activity, Respiration at 1 and 5 minutes; score ≥7 is normal.

Neonatal jaundice: physiological jaundice appears after 24 hours and peaks at day 3-5; jaundice within 24 hours is always pathological (hemolysis, sepsis, biliary atresia).

Growth: birth weight doubles by 5 months and triples by 12 months; length increases about 25 cm in the first year.

Kawasaki disease: fever ≥5 days plus 4 of 5 criteria (conjunctivitis, mucosal changes, rash, extremity changes, cervical lymphadenopathy); IVIG plus aspirin prevents coronary aneurysms.

Nephrotic syndrome in children: minimal change disease is commonest; treat with corticosteroids; biopsy if steroid-resistant or atypical features.

Intussusception: infant with intermittent colicky pain, drawing up legs, and red currant jelly stool; ultrasound shows target sign; air enema is diagnostic and therapeutic.

Acute epiglottitis: drooling, tripod position, muffled voice, and high fever; avoid throat examination and secure the airway in the operating room.

Croup: barking cough, hoarseness, inspiratory stridor; treat with dexamethasone and nebulized epinephrine for moderate-severe cases.

Anatomy: the femoral nerve (L2-L4) supplies the anterior thigh and quadriceps; the femoral artery lies within the femoral triangle bounded by the inguinal ligament, sartorius, and adductor longus.

Physiology: cardiac output = heart rate × stroke volume; stroke volume is determined by preload, afterload, and contractility (Frank-Starling relationship).

Renal physiology: glomerular filtration rate = Kf × net filtration pressure; inulin clearance measures GFR; PAH clearance measures renal plasma flow.

Biochemistry: glycolysis yields net 2 ATP and 2 NADH per glucose; the Krebs cycle and oxidative phosphorylation yield about 30-32 ATP in total.

Enzyme kinetics: Michaelis-Menten Km is the substrate concentration at half Vmax; a low Km indicates high affinity; competitive inhibitors raise Km without changing Vmax.

Pathology: acute inflammation features vasodilation, increased vascular permeability, and neutrophil emigration; chronic inflammation features lymphocytes, plasma cells, and macrophages.

Neoplasia: tumor suppressor genes (p53, Rb, APC) require loss of both alleles; oncogenes (RAS, MYC) require activation of one allele.

Pharmacology: first-order elimination means a constant fraction is removed per unit time; half-life = 0.693 × volume of distribution / clearance.

Microbiology: gram-positive cocci in clusters = Staphylococcus; in chains = Streptococcus; catalase test distinguishes the two; coagulase distinguishes S. aureus.

Incidence measures new cases over a period and estimates risk; prevalence measures all existing cases and equals incidence × mean duration of disease.

Sensitivity = true positives / (true positives + false negatives); specificity = true negatives / (true negatives + false positives).

Positive predictive value depends on prevalence; it rises as prevalence increases, whereas sensitivity and specificity are intrinsic to the test.

Relative risk is used in cohort studies; odds ratio approximates relative risk in case-control studies when the disease is rare.

Attack rate = new cases / population at risk during an outbreak; case fatality rate = deaths / diagnosed cases.

Herd immunity threshold depends on the basic reproduction number: threshold = 1 − 1/R0.

Levels of prevention: primary (pre-disease, e.g., immunization), secondary (early detection, e.g., screening), tertiary (disability limitation and rehabilitation).

Epidemiological study hierarchy: randomized controlled trials provide the strongest evidence for causality; case reports provide the weakest.

Water and sanitation: chlorination is the most effective point-of-use disinfection; coliform counts indicate fecal contamination.

Depression: diagnosis requires ≥5 of 9 symptoms for ≥2 weeks, including depressed mood or anhedonia; first-line treatment is SSRIs or psychotherapy.

Bipolar disorder: mania requires elevated or irritable mood with increased energy for ≥1 week plus ≥3 symptoms; treat acute mania with mood stabilizers and antipsychotics; avoid antidepressants alone.

Schizophrenia: ≥2 of delusions, hallucinations, disorganized speech, grossly disorganized behavior, or negative symptoms for ≥6 months with ≥1 month of active symptoms.

Serotonin syndrome: clonus, hyperreflexia, agitation, and hyperthermia after serotonergic drugs; treat with cyproheptadine and supportive care.

Neuroleptic malignant syndrome: rigidity, hyperthermia, autonomic instability, and elevated creatine kinase after antipsychotics; treat with dantrolene or bromocriptine.

Delirium: acute fluctuating disturbance of attention and awareness, often due to infection, drugs, or metabolic causes; it is a medical emergency.

Defense mechanisms: denial, projection, displacement, rationalization, and sublimation (the only mature defense).

Alcohol withdrawal: tremor, agitation, and seizures 6-48 hours after the last drink; treat with benzodiazepines and thiamine to prevent Wernicke encephalopathy.

Grief versus major depression: grief features waves of sadness tied to thoughts of the deceased with preserved self-esteem; depression features persistent low mood and worthlessness.

Informed consent requires capacity, adequate disclosure of risks/benefits/alternatives, comprehension, and voluntariness; it must be obtained before any procedure.

Confidentiality may be breached only with patient consent, legal requirement (e.g., notifiable diseases), or overriding public interest.

Death: brainstem death is defined by absent brainstem reflexes and apnea test after exclusion of reversible causes; it requires two independent senior doctors.

Rigor mortis begins 1-2 hours after death, peaks at 12 hours, and resolves by 24-48 hours; livor mortis appears 1-2 hours after death and fixes by 6-8 hours.

Carbon monoxide poisoning: cherry-red skin and carboxyhemoglobin levels; treat with 100% oxygen and hyperbaric oxygen for severe cases.

Organophosphate poisoning: miosis, salivation, lacrimation, bradycardia, and fasciculations; treat with atropine and pralidoxime.

Ethical principles: autonomy, beneficence, non-maleficence, and justice; autonomy generally takes priority in competent adult decisions.

Fitness to stand trial requires understanding of charges, ability to instruct counsel, and comprehension of proceedings; insanity defense requires inability to know the nature/wrongfulness of the act.

Acute otitis media: bulging erythematous tympanic membrane and middle ear effusion; first-line treatment is amoxicillin; watchful waiting for mild cases in children >2 years.

Cholesteatoma: painless foul-smelling ear discharge with attic perforation; treatment is surgical removal (mastoidectomy).

Vertigo: benign paroxysmal positional vertigo is diagnosed by the Dix-Hallpike test and treated with the Epley maneuver.

Epistaxis: most cases arise from Kiesselbach's plexus on the anterior septum; treat with pressure, topical vasoconstrictors, and cautery.

Acute angle-closure glaucoma: painful red eye, fixed mid-dilated pupil, hazy cornea, and high intraocular pressure; treat with topical timolol, pilocarpine, IV acetazolamide, and laser iridotomy.

Cataract: painless progressive loss of vision with lens opacity; surgery is the only definitive treatment.

Papilledema: bilateral optic disc swelling from raised intracranial pressure; it preserves visual acuity but enlarges the blind spot.

Retinopathy of prematurity: occurs in premature infants exposed to supplemental oxygen; screening is by dilated fundoscopy, and treatment is laser photocoagulation for severe disease.

Horner syndrome: ptosis, miosis, and anhidrosis from sympathetic pathway interruption; a pancoast tumor is a classic cause.

ASA physical status: I = healthy; II = mild systemic disease; III = severe systemic disease; IV = severe disease that is a constant threat to life; V = moribund; VI = brain-dead organ donor.

Spinal anesthesia: local anesthetic injected into the subarachnoid space; complications include hypotension, post-dural puncture headache, and high spinal block.

Malignant hyperthermia: triggered by volatile anesthetics and succinylcholine; treat with dantrolene and cooling measures; monitor end-tidal CO2 and temperature.

Local anesthetic toxicity: perioral numbness, seizures, and cardiac arrest; treat with 20% lipid emulsion (Intralipid).

Radiology: the chest radiograph is taken PA with a 6-foot distance; the heart size is assessed as cardiothoracic ratio <0.5.

CT versus MRI: CT is faster and better for bone and acute hemorrhage; MRI has superior soft tissue contrast and no ionizing radiation.

Ultrasound: air and bone reflect sound waves, so the modality is poor for lung and bone evaluation; it is first-line for gallstones and obstetric imaging.

Contrast media: iodinated contrast can cause anaphylactoid reactions and contrast-induced nephropathy; metformin should be withheld if renal function is impaired.

Radiation safety: ALARA (as low as reasonably achievable); lead aprons and collimation reduce dose; pregnancy should be disclosed before any ionizing imaging.

Acute MI diagnosis requires cardiac troponin rise/fall with symptoms, ECG changes, or imaging; STEMI needs ST elevation in two contiguous leads.

Heart failure with reduced ejection fraction (≤40%) is treated with ACE inhibitor/ARNI, beta-blocker, MRA, and SGLT2 inhibitor.

Diabetic ketoacidosis is diagnosed with glucose >250 mg/dL, pH <7.3, bicarbonate <18 mEq/L, and ketonemia.

Hyperkalemia with ECG changes is treated first with IV calcium, then insulin-glucose and salbutamol.

Nephrotic syndrome is defined by proteinuria >3.5 g/day, hypoalbuminemia, edema, and hyperlipidemia.

Cirrhotic ascites with SAAG ≥1.1 g/dL indicates portal hypertension; first-line therapy is spironolactone plus furosemide.

Microcytic anemia (MCV <80) suggests iron deficiency, thalassemia, or chronic disease; macrocytic anemia suggests B12/folate deficiency.

Acute appendicitis presents with periumbilical pain migrating to the right iliac fossa with McBurney point tenderness.

Small bowel obstruction shows multiple air-fluid levels on erect film; initial management is nil by mouth, IV fluids, and nasogastric decompression.

Shock index (heart rate/systolic blood pressure) >0.9 suggests significant occult hemorrhage.

Parkland formula for burns is 4 mL × weight (kg) × %TBSA lactated Ringer's in 24 hours, half in the first 8 hours.

Sentinel lymph node biopsy is standard for clinically node-negative axilla in breast cancer.

Recurrent laryngeal nerve injury after thyroidectomy causes hoarseness; external branch of superior laryngeal nerve injury causes loss of high pitch.

Acute pancreatitis is diagnosed by 2 of 3 criteria: characteristic pain, lipase >3× upper limit, or imaging.

Naegele's rule estimates delivery date as first day of last menstrual period + 7 days − 3 months.

Preeclampsia is new hypertension ≥140/90 mmHg after 20 weeks with proteinuria ≥300 mg/24 h or organ dysfunction.

Postpartum hemorrhage is most commonly caused by uterine atony; first-line treatment is uterine massage and oxytocin.

Ectopic pregnancy presents with amenorrhea, abdominal pain, and vaginal bleeding; transvaginal ultrasound shows an empty uterus.

Late decelerations indicate uteroplacental insufficiency; variable decelerations indicate cord compression.

Cervical cancer screening uses Pap smear or HPV testing; HPV 16 and 18 cause most cases.

Ovarian torsion presents with sudden unilateral pelvic pain and an enlarged ovary on ultrasound; laparoscopy is diagnostic and therapeutic.

Neonatal resuscitation begins with warmth, drying, stimulation, and airway positioning; positive pressure ventilation is the key step for bradycardia <100/min.

APGAR score assesses Appearance, Pulse, Grimace, Activity, and Respiration at 1 and 5 minutes.

Jaundice within 24 hours of birth is always pathological and requires investigation.

Birth weight doubles by 5 months and triples by 12 months; length increases about 25 cm in the first year.

Kawasaki disease is fever ≥5 days plus 4 of 5 criteria; treat with IVIG and aspirin to prevent coronary aneurysms.

Intussusception presents with colicky pain, drawing up of legs, and red currant jelly stool; air enema is diagnostic and therapeutic.

Croup is treated with dexamethasone and nebulized epinephrine for moderate-severe cases.

The femoral nerve (L2-L4) supplies the anterior thigh and quadriceps; the femoral artery lies in the femoral triangle.

Cardiac output = heart rate × stroke volume; stroke volume depends on preload, afterload, and contractility.

Inulin clearance measures glomerular filtration rate; PAH clearance measures renal plasma flow.

Glycolysis yields net 2 ATP and 2 NADH per glucose; total ATP from glucose oxidation is about 30-32.

Michaelis-Menten Km is the substrate concentration at half Vmax; competitive inhibitors raise Km without changing Vmax.

Acute inflammation features neutrophil emigration; chronic inflammation features lymphocytes and macrophages.

Tumor suppressor genes (p53, Rb, APC) require loss of both alleles; oncogenes (RAS, MYC) require activation of one allele.

Incidence measures new cases over time; prevalence measures all existing cases and equals incidence × mean duration.

Sensitivity = true positives / (true positives + false negatives); specificity = true negatives / (true negatives + false positives).

Positive predictive value rises as disease prevalence increases, whereas sensitivity and specificity are intrinsic to the test.

Relative risk is used in cohort studies; odds ratio approximates relative risk in case-control studies when disease is rare.

Attack rate = new cases / population at risk during an outbreak; case fatality rate = deaths / diagnosed cases.

Herd immunity threshold = 1 − 1/R0, where R0 is the basic reproduction number.

Primary prevention occurs before disease (immunization); secondary prevention is early detection (screening); tertiary prevention is rehabilitation.

Major depression requires ≥5 of 9 symptoms for ≥2 weeks, including depressed mood or anhedonia.

Mania requires elevated or irritable mood with increased energy for ≥1 week plus ≥3 symptoms; avoid antidepressants alone.

Schizophrenia requires ≥2 core symptoms for ≥6 months with ≥1 month of active symptoms.

Serotonin syndrome features clonus, hyperreflexia, agitation, and hyperthermia; treat with cyproheptadine.

Neuroleptic malignant syndrome features rigidity, hyperthermia, autonomic instability, and elevated creatine kinase; treat with dantrolene.

Delirium is an acute fluctuating disturbance of attention and awareness, often due to infection, drugs, or metabolic causes.

Alcohol withdrawal causes tremor, agitation, and seizures 6-48 hours after the last drink; treat with benzodiazepines and thiamine.

Informed consent requires capacity, adequate disclosure, comprehension, and voluntariness before any procedure.

Confidentiality may be breached only with consent, legal requirement, or overriding public interest.

Brainstem death requires absent brainstem reflexes and a positive apnea test after excluding reversible causes.

Rigor mortis begins 1-2 hours after death, peaks at 12 hours, and resolves by 24-48 hours.

Carbon monoxide poisoning causes cherry-red skin; treat with 100% oxygen and hyperbaric oxygen for severe cases.

Organophosphate poisoning causes miosis, salivation, lacrimation, bradycardia, and fasciculations; treat with atropine and pralidoxime.

Ethical principles are autonomy, beneficence, non-maleficence, and justice; autonomy generally prevails in competent adult decisions.

Acute otitis media shows a bulging erythematous tympanic membrane; first-line treatment is amoxicillin.

Cholesteatoma causes painless foul-smelling ear discharge with attic perforation; treatment is surgical removal.

Benign paroxysmal positional vertigo is diagnosed by the Dix-Hallpike test and treated with the Epley maneuver.

Acute angle-closure glaucoma presents with a painful red eye, fixed mid-dilated pupil, hazy cornea, and high intraocular pressure.

Papilledema is bilateral optic disc swelling from raised intracranial pressure; visual acuity is preserved but the blind spot enlarges.

Retinopathy of prematurity occurs in premature infants exposed to supplemental oxygen; severe disease is treated with laser photocoagulation.

Horner syndrome features ptosis, miosis, and anhidrosis; a Pancoast tumor is a classic cause.

ASA physical status: I = healthy; II = mild systemic disease; III = severe systemic disease; IV = severe disease that is a constant threat to life.

Spinal anesthesia injects local anesthetic into the subarachnoid space; complications include hypotension and post-dural puncture headache.

Malignant hyperthermia is triggered by volatile anesthetics and succinylcholine; treat with dantrolene.

Local anesthetic toxicity causes perioral numbness, seizures, and cardiac arrest; treat with 20% lipid emulsion.

The chest radiograph is taken PA at 6 feet; cardiothoracic ratio <0.5 is normal.

CT is faster and better for bone and acute hemorrhage; MRI has superior soft tissue contrast and no ionizing radiation.

Iodinated contrast can cause anaphylactoid reactions and contrast-induced nephropathy; withhold metformin if renal function is impaired.

Radiation safety follows ALARA; lead aprons and collimation reduce dose; pregnancy should be disclosed before ionizing imaging.